Within the scope of treatments for vertebroplasty and kyphoplasty, mixed pastes are employed to fill and stabilize vertebra, e.g., with recent fractures.
The bone cement required for this consists either of hydroxyl apatite, a calcium phosphate salt, or of acrylates. Both types are mixed of two components, one solid and one liquid, and set in situ.
Various devices and methods are known for mixing bone cement. Thus, EP 0 178 658 A2 describes a device and method for the manufacture of bone cement for the purpose of anchoring prosthetics, such as artificial hip joints. The device comprises a vessel in which bone cement is mixed by means of a motor-driven stirrer. The vigorous stirring leads to inclusions of air in the mixture of bone cement, which must be removed. Connected to the mixing vessel for said purpose is a suction pump, which, during the mixing process produces a vacuum inside the vessel. During extraction of the bone cement, air is prevented from reaching the extraction syringe.
The stirrer and requisite pump are cost-intensive. A further disadvantage is that the known device can only be used to mix substantial amounts of bone cement.